This invention relates to improvements to anvils used in centrifugal impact crushers.
Centrifugal impact crushing machines are used to crush rock and other materials by depositing the material on a horizontal rotating table where centrifugal force causes the material to be thrown off the table and strike stationary anvils located around the periphery of the table, thereby causing the material to fracture on impact. In order to break the material, it is hurled at the anvils at high speeds. The anvils are attached to fixtures that are mounted around the periphery of the crusher housing. Thus, the fixtures are subject to high impact loads and the fixtures and the fasteners used to join the anvils to the fixture are prone to premature failure.
An example of the prior anvil design art is shown in FIG. 2 of Ackers et al., U.S. Pat. No. 4,090,673. The anvils are retained by pins 76 mounted in the backs of the anvils that slide into slots in fixtures 78 mounted on the inside wall of the crusher housing 70. This design causes problems because the severe impact loads on the anvils can cause the pins 76 to break. When a pin breaks, the anvil falls to the bottom of the housing and, unless the machine is shut down, material will continue to strike the area of the missing anvil and cause damage to the fixture and the inner wall of the housing. This problem gave rise to the need for a method of mounting the anvils that will withstand the severe impact loads.